Interesting to hear confirmation of the tonal noise of the higher RPM Gentle Typhoons. I currently have two of these sitting idle in my box o' fans for this very reason. One of these is the 1850 RPM mentioned in the article, but the other is an 1150, which unfortunately exhibits the ringing tone when the voltage is turned down.

I've had mixed results with the GTs, a couple have had issues with ringing and chatter, most have been fine.

Does anyone know how these results apply when it comes to case fans? It seems to me that a case fan would require much less static pressure and more airflow. I'm a bit surprised that there wasn't a test procedure designed to test performance when mounted as a case fan since it should be different conditions and different results. Am I wrong? Can these measurements be used? Because it seems to me that a scythe GT will most likely fall behind a nexus fan when mounted as a case fan since the 11 blades wouldn't be very useful when it's just about moving air compared to the 7 blade design from the nexus. I'm wondering because I need to decide on fans for my upcoming build ^^

ps. would the front fans on a door-design case like the fractal design r3 or corsair 550d take advantage of a higher static pressure because of obstructed intake?

Does anyone know how these results apply when it comes to case fans? It seems to me that a case fan would require much less static pressure and more airflow. I'm a bit surprised that there wasn't a test procedure designed to test performance when mounted as a case fan since it should be different conditions and different results.

Well, FWIW, the FPM measurements (and SPL) are done in free air and not while the fans are mounted on the heatsink.

in case you did not get the msg in the review, airflow by itself is completely meaningless, and there is no way my single anemometer can give an accurate cfm. It has to be tied to pressure measurements as well, and both these vary with rpm, like spl.

Some simple notes -

--Fans with high pressure at low speed are ideal for silencers. --The fans which gave lower temps at low speed will also do better than others at those speeds as case fans when there is some but not very high impedance -- which describes the archon.

Gotta run -- more later.

----------------

LATER:

Going back to comparisons of the results, I caution everyone not to...-- celebrate differences of 1C in temperature or 1 dBA in noise. Even though the results are probably accurate enough to better than those numbers, the actual performance oor audible difference is just too small to be significant for just about anyone. Can I hear the difference, for example, 11 and 12 dBA fans when they are inside a sturdy case, perhaps with one or more noise sources within (even if they are very quiet) or any ambient noise around me (like my own typing?) No, it's almost impossible.

Whether higher pressure or higher airflow is better for case fan is probably going to raise debate. It depends, as usual, on just what the rpm is, and how much impedance there is. In fans with big area blades are going to give higher pressure but will cause more noise. A simple rule of thumb for me is to look at thefan -- if the gaps between the blades are small or non-existent, then it's probably going to give higher pressure at the cost of higher noise, and of course the reverse -- thin, small blades with big gaps between just can't apply as much pressure.

When it is on a low impedance heatsink (ie, one which has wide gaps between fins and short distance for the air to flow through), a higher speed fan with lower fan blade area will probably work best -- again depending on the noise/cooling balance you want/need.

On a higher impedance heatsink, a fan that can provide higher pressure at lower speed will do better.

So there is no perfect fan, just which fan works best for your setup, depending on your goals.

But if asked what's the perfect fan for a silencer, I'd have to answer high pressure at low speed (noise). This is the best general purpose silencer's fan -- ilke a car with a powerful electric motor that has great torque at <20 mph while barely making any noise.

Interesting to hear confirmation of the tonal noise of the higher RPM Gentle Typhoons. I currently have two of these sitting idle in my box o' fans for this very reason. One of these is the 1850 RPM mentioned in the article, but the other is an 1150, which unfortunately exhibits the ringing tone when the voltage is turned down.

I've had mixed results with the GTs, a couple have had issues with ringing and chatter, most have been fine.

It seems there's sample variances between Gentle Typhoons. I got one GT1450 which was very quiet at 5V/7v, and it managed to surprise me given its smooth turbulence, no ball-bearing chatter characteristics.

Glad to see the Gentle Typhoons finally got attention. I put 5 of the 1150 rpm fans in a build almost 3 years ago (Aug 09). I'm very happy with their performance and silence. I've never noticed unusual noise or anything other than their unobtrusive signature sound. 5 fans running full speed and very nearly inaudible from a case under my desk and beside my right leg. Unfortunately it seems many models of the GT fans have been discontinued. They could have used SPCR's review attention some time ago.

Link to the old thread where the Gentle Typhoons were discussed with a link to pictures of my build:

It's not entirely exact: it depends of the platform (you're using older, partial data).

With the overclocked Core i5 (the new SPCR test bed), the stock Noctua are clearly less effective than a single, cheap Nexus down to 14dBA, while they have a slight advantage over it of just 1°C only at the lowest 12dBA level. See: http://www.silentpcreview.com/article1267-page5.html

It's a bit unfortunate that the GT is discontinued. The real winner for me from this review is the Nexus. Running it at 700 RPM (~7V) gets it pretty close to the performance of the Noiseblocker or the GT and it's half the price and widely available.

Yes, the 2 noctuas slightly outperform the single nexus on that heatsink in particular, so swapping them out would obviously be a Bad Idea(tm).

But I was more interested in fan-vs-fan performance in my question. And I do believe the answer is "1 new Nexus outperforms 1 new Noctua where SPCR reader interests are concerned".

Having said that, I would like more info on how Nexus vs Noctua fans degrade over time. I have a decent confidence in Noctua myself, but Nexus I do not know enough about. Price wise you can buy 2 Nexus for 1 Noctua, but if 50% of the Nexus' life is spent squealing and humming I'd still shop Noctua. But I don't know if that's the case - anyone with insights? =)

squealing and humming is not what happens to sleeve bearing fans as they age. "chuffing" is more likely -- this is the sound I hear most from slightly damaged or worn sleeve bearing fans. We also have really old Nexus 120 fans that are still being used in the lab -- like 8 years old! -- and they're still OK. Lots of handling abuse, but much less actual spinning than fans employed in normal PCs.

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